Before going into more detail about anxiety attacks, let’s first take a quick look at the body’s fear response, because anxiety is all about fear.  A fear instinct can be very important to the survival of a species.  When an animal senses danger, the fear response is triggered so that the animal can respond to the danger appropriately.  This is known as the ‘fight-or-flight’ response (or sometimes the ‘fight, flight or freeze’ response).  The animal may flee to safety, or prepare to fight an enemy, or may even ‘freeze’ in an attempt to avoid detection.  In modern-day life we do not often have to run from predators or fight enemies, however the response can still be useful in some situations of physical danger.  

Many present day situations that cause us to feel fear are not about physical danger.  We may feel fear in situations where we are under pressure to perform, such as when taking an examination or giving a speech to a large group of people.  We may also worry and feel fearful about things we have very little control over, such as being a passenger on an aeroplane.  Whatever the trigger, the physiological response is much the same.  The sympathetic nervous system is stimulated.  

In our bodies, the autonomic nervous system (‘automatic’ part of the nervous system) has two subsystems called the sympathetic and the parasympathetic.  These two subsystems are in a kind of balance with each other, so that when one is more active the other is less active.  The sympathetic side is more active when we are more active, and the parasympathetic is more active when we are at rest and our body is digesting nutrients and doing repairs and restorative work.  During the fear response, sympathetic activity increases hugely, and parasympathetic functions such as digestion and repair shut down.  The body is preparing for action, possibly of an extreme kind – fighting for or running for your life.
 
Various parts of the brain and nervous system are involved in this response.  The adrenal glands (which sit on top of the kidneys) release a hormone called epinephrine – otherwise known as adrenaline – which produces a whole set of responses in the body.  Everyone has heard of adrenaline – we talk about an ‘adrenaline rush’ when we do something scary and/or exciting such as go on a roller coaster ride.  The body can’t really tell the difference between excitement and fear, it’s all in how we perceive the event.  If we enjoy roller coaster rides, we won’t be afraid and it will seem exciting, but if we don’t like them it may seem very scary.

What happens in the body during the ‘fight-or-flight’ response?

• Breathing rate increases – to get plenty of oxygen into your blood
• Heart beats faster and stronger – it needs to pump lots of oxygenated blood to your muscles
• Blood is redirected to the skeletal muscles – so that we can fight or run away
• Digestive processes reduce – you might experience stomach ache or nausea
  
• Salivation reduces  – you might experience a dry mouth
• Perspiration increases
• Pupils dilate – so you can see (the danger, your escape route, etc.) more clearly
• Increased alertness, senses may become more sensitive
  

These things also happen during some normal activities that are not associated with fear, such as during physical exercise.  The sympathetic and parasympathetic are always finding the right balance according to the needs of the body at the time.  When we are exercising, we expect to breathe faster and harder, we expect our hearts to pump faster and for our skin to perspire.  This is all normal stuff and not scary at all to most of us.

So far, so good, this is all normal stuff…